<template>
  <div>
    <el-switch
      v-model="draggable"
      active-color="#13ce66"
      inactive-color="#ff4949"
      active-text="开启拖拽"
      inactive-text="关闭拖拽">
    </el-switch>
    <el-button @click="batchSave" v-show="draggable">批量保存</el-button>
    <el-tree :data="data" :props="defaultProps"
             :expand-on-click-node="false"
             show-checkbox node-key="catId"
             :default-expanded-keys="expandedKey"
             :draggable="draggable"
             @allow-drop="allowDrop"
             @node-drop="handleDrop"
    >
      <span class="custom-tree-node" slot-scope="{ node, data }">
        <span>{{ node.label }}</span>
        <span>
          <el-button
              v-if="node.level <=2"
              type="text"
              size="mini"
              @click="() => append(data)">
            Append
          </el-button>
          <el-button
              type="text"
              size="mini"
              @click="() => edit(data)">
            Edit
          </el-button>
          <el-button
              v-if="node.childNodes.length==0"
              type="text"
              size="mini"
              @click="() => remove(node, data)">
            Delete
          </el-button>
        </span>
      </span>
    </el-tree>
    <el-dialog
        :title="title"
        :visible.sync="dialogVisible"
        :close-on-click-modal="false"
        width="500px"
        :before-close="handleClose">
      <el-form :model="form" :inline="true" :label-width="formLabelWidth" ref="form">
        <el-form-item label="分类名称" prop="name">
          <el-input v-model="form.name" placeholder="请输入内容"></el-input>
        </el-form-item>
        <el-form-item label="图标" prop="icon">
          <el-input v-model="form.icon"></el-input>
        </el-form-item>
      </el-form>
      <span slot="footer" class="dialog-footer">
        <el-button @click="cancel">取 消</el-button>
        <el-button type="primary" @click="submitForm">确 定</el-button>
       </span>
    </el-dialog>
  </div>
</template>

<script>
export default {
  name: 'category',
  data () {
    return {
      draggable: false,
      updateNodes: [],
      title: '对话框',
      formLabelWidth: '100',
      form: {
        name: '',
        parentCid: 0,
        catLevel: 0,
        showStatus: 1,
        sort: 0,
        productUnit: '',
        icon: '',
        catId: null
      },
      dialogVisible: false,
      data: [],
      defaultProps: {
        children: 'children',
        label: 'name'
      },
      expandedKey: [],
      maxLevel: 0,
      pCid: []
    }
  },
  created () {
    this.getMenus()
  },
  methods: {
    batchSave () {
      this.$http({
        url: this.$http.adornUrl('/product/category/update/sort'),
        method: 'post',
        data: this.$http.adornData(this.updateNodes, false)
      }).then(({data}) => {
        this.$message({
          message: '菜单顺序修改成功',
          type: 'success'
        })
        // 刷新出新的菜单
        this.getMenus()
        // 展开菜单
        this.expandedKey = [this.pCid]
        this.updateNodes = []
        this.maxLevel = 0
        this.pCid = 0
      })
    },
    handleDrop (draggingNode, dropNode, dropType, ev) {
      console.log('handleDrop: ', draggingNode, dropNode, dropType)
      // 1、当前节点最新的父节点id
      let pCid = 0
      let siblings = null
      if (dropType === 'before' || dropType === 'after') {
        pCid =
            dropNode.parent.data.catId === undefined
                ? 0
                : dropNode.parent.data.catId
        siblings = dropNode.parent.childNodes
      } else {
        pCid = dropNode.data.catId
        siblings = dropNode.childNodes
      }
      this.pCid.push(pCid)

      // 2、当前拖拽节点的最新顺序，
      for (let i = 0; i < siblings.length; i++) {
        if (siblings[i].data.catId === draggingNode.data.catId) {
          // 如果遍历的是当前正在拖拽的节点
          let catLevel = draggingNode.level
          if (siblings[i].level !== draggingNode.level) {
            // 当前节点的层级发生变化
            catLevel = siblings[i].level
            // 修改他子节点的层级
            this.updateChildNodeLevel(siblings[i])
          }
          this.updateNodes.push({
            catId: siblings[i].data.catId,
            sort: i,
            parentCid: pCid,
            catLevel: catLevel
          })
        } else {
          this.updateNodes.push({catId: siblings[i].data.catId, sort: i})
        }
      }
      // 3、当前拖拽节点的最新层级
    },
    updateChildNodeLevel (node) {
      if (node.childNodes.length > 0) {
        for (let i = 0; i < node.childNodes.length; i++) {
          let cNode = node.childNodes[i].data
          this.updateNodes.push({
            catId: cNode.catId,
            catLevel: node.childNodes[i].level
          })
          this.updateChildNodeLevel(node.childNodes[i])
        }
      }
    },
    allowDrop (draggingNode, dropNode, type) {
      // 被拖动的当前节点以及所在的父节点总层数不能大于3
      // 被拖动的当前节点总层数
      this.countNodeLevel(draggingNode.data)
      // 正在拖动的节点 + 父节点所在的深度不大于3即可
      let deep = Math.abs(this.maxLevel - draggingNode.level) + 1
      if (type === 'inner') {
        return deep + dropNode.level <= 3
      } else {
        return deep + dropNode.parent.level <= 3
      }
    },
    cancel () {
      this.$refs.form.resetFields()
      this.form = {
        name: '',
        parentCid: 0,
        catLevel: 0,
        showStatus: 1,
        sort: 0,
        productUnit: '',
        icon: '',
        catId: null
      }
      this.dialogVisible = false
    },
    submitForm () {
      if (this.form.catId) {
        let {catId, name, icon, productUnit} = this.form
        let data = {catId, name, icon, productUnit}
        this.$http({
          url: this.$http.adornUrl('/product/category/update'),
          method: 'post',
          data: this.$http.adornData(data, false)
        }).then(({data}) => {
          this.$message({
            message: '编辑成功',
            type: 'success'
          })
          this.dialogVisible = false
          this.form = {}
          // 刷新出新的菜单
          this.getMenus()
          // 展开菜单
          this.expandedKey = [this.form.catId]
        })
      } else {
        this.$http({
          url: this.$http.adornUrl('/product/category/save'),
          method: 'post',
          data: this.$http.adornData(this.form, false)
        }).then(({data}) => {
          this.$message({
            message: '新增成功',
            type: 'success'
          })
          this.dialogVisible = false
          this.form = {}
          // 刷新出新的菜单
          this.getMenus()
          // 展开菜单
          this.expandedKey = [this.form.parentCid]
        })
      }
    },
    handleClose (done) {
      this.$confirm('确认关闭？')
          .then(_ => {
            done()
          })
          .catch(_ => {
          })
    },
    edit (data) {
      this.title = '编辑菜单'
      this.$http({
        url: this.$http.adornUrl('/product/category/info/' + data.catId),
        method: 'get',
        params: this.$http.adornParams({})
      }).then(({data}) => {
        this.dialogVisible = true
        this.form.name = data.data.name
        this.form.catId = data.data.catId
        this.form.icon = data.data.icon
        this.form.productUnit = data.data.productUnit
        this.form.parentCid = data.data.catId
      })
    },
    append (data) {
      this.title = '新增菜单'
      this.dialogVisible = true
      this.form.parentCid = data.catId
      this.form.catLevel = data.catLevel * 1 + 1
    },

    remove (node, data) {
      let ids = [data.catId]
      this.$confirm(`是否删除【${data.name}】菜单?`, '提示', {
        confirmButtonText: '确定',
        cancelButtonText: '取消',
        type: 'warning'
      })
          .then(() => {
            this.$http({
              url: this.$http.adornUrl('/product/category/delete'),
              method: 'post',
              data: this.$http.adornData(ids, false)
            }).then(({data}) => {
              this.$message({
                message: '菜单删除成功',
                type: 'success'
              })
              // 刷新出新的菜单
              this.getMenus()
              // 设置需要默认展开的菜单
              this.expandedKey = [node.parent.data.catId]
            })
          })
          .catch(() => {
          })
    },
    getMenus () {
      this.dataListLoading = true
      this.$http({
        url: this.$http.adornUrl('/product/category/list/tree'),
        method: 'get'
      }).then(({data}) => {
        this.data = data.data
        this.dataListLoading = false
      })
    },
    countNodeLevel (node) {
      // 找到子节点，求出最大深度
      if (node.children != null && node.children.length > 0) {
        node.children.forEach((item, index) => {
          if (node.children[index].catLevel > this.maxLevel) {
            this.maxLevel = node.children[index].catLevel
          }
          this.countNodeLevel(node.children[index])
        })
      }
    }
  }
}
</script>

<style scoped>

</style>
